The present invention relates to a method for producing a grain-oriented electrical steel sheet or strip (hereinafter referred to as sheet) having the grain orientation {110}&lt;001&gt; which is easily magnetizable in the rolling direction.
The grain oriented electrical steel sheet is required to have a high magnetic flux density and low watt loss characteristic.
Recently, great importance has been put on the minimization of size as well as the improvement of performance of transformers, etc., and for this purpose it is necessary to reduce the weight of iron cores for such applications. In general, in order to reduce the iron core weight, the iron core must be used in a range of high magnetic flux density so that a material having good magnetization characteristics, namely a high B.sub.8 (a magnetic flux density at a magnetizing force 800 AT/cm), must be used for the iron cores.
Meanwhile, when it is used at a high magnetic flux density, the watt loss will increase and in this case it is noticeable that the watt loss of a material having higher B.sub.8 is far much smaller than that of a material having a lower B.sub.8 in a high magnetic flux zone, and yet the increasing rate of the watt loss accompanying the increase of the magnetic flux density is lower in the case of the material having high B.sub.8.
The present invention provides a method which can produce steel products satisfying the above requirements, namely a high magnetic flux density grain-oriented electrical steel sheet having remarkably excellent excitation characteristic, namely an excellent B.sub.8 characteristic of more than 1.90 wb/m.sup.2 as compared with a conventional grain-oriented electrical steel sheet.